Externally heated, revolving furnace



Feb. 16, 1954 p BEETZ EXTERNALLY HEATED, REVOLVING FURNACE 2 Sheets-Sheet 1 Filed Jan. 28 1952 Illallll Feb. 16, 1954 P. BEETZ EXTERNALLY HEATED, REVOLVING FURNACE 2 Sheets-Sheet 2 Filed Jan. 28, 1952 Patented Feb. 16, 1954 EXTERNALLY HEATED, REVOLVING FURNACE Pierre Beetz, Liege, Belgium, assignor to Industrial and Financial Association Inc., Panama,

Republic of Panama Application January 28, 1952, Serial No. 268,619

Claims priority, application France January 30, 1951 4 Claims.

The invention relates to an externally heated, revolving furnace which may be used c. g. in remelting metals, of the type including a drum from refractory material, which is held together by an outer metal casing comprising a circumferential section connected to end discs from metal arranged outside the heated enclosure in which the body of the drum is arranged. Known constructions of this type dont make it possible to compensate in a suitable manner the differential expansion of the refractory lining and the metal casing, both in length and in diameter, the difference in expansion between the said two sections of the furnace being important mainly where cold material to be treated is charged into the furnace. As a result of the fact that the expansion of the metal casing is definitely most important, cracks occur in the refractory lining, especially at the joints of the component members thereof, with possible leakage of metal under treatment and rapid destruction of the lining and of the metal casing.

The invention has for its object to eliminate the aforesaid drawbacks and, to this end, provides that, in a revolving furnace of the type specified, the circumferential section of the metal casing is comprised of bars which are mutually spaced apart a distance sufficiently small to enable them to support effectively the refractory lining and are free from any mutual connection as far as their respective sections situated within the heated enclosure are concerned, the said bars being connected to the two end discs situated outside the said enclosure, an additional disc being arranged at least at one of the said ends, between the corresponding end disc from which the additional disc is spaced axially and the refractory lining against which the said additional disc is pressed by resilient, advantageously adjustable means which are supported by the said end disc.

Other features and advantages will appear from the disclosure of one way of carrying out the invention, which will be given hereinafter with reference to the enclosed diagrammatic drawings, wherein:

Fig. 1 is a vertical central section of a revolving furnace according to the invention;

Fig. 2 is a side view of the furnace;

Fig. 3 is a transverse sectional view of the revolving drum of the furnace, and

Figs. 4 and 5 are fragmentary views, to a larger scale, of one end of the drum, taken along two different radial cross sections.

In the example shown, the furnace includes a structure I made from refractory material, which defines the heated space with the body of a revolving drum extending across such space, which drum includes a metal casing formed by assembling two discs '2, 3 and bars 4, the said casing being adapted to embrace and support the refractory lining 5. The transverse walls of the latter are arranged slightly inwardly of the ends of the cylindrical portion of the lining, the cavities which are thus formed outside the said walls being filled with insulating material 6, e. g asbestos. The discs 2, 3 are fast with trunnions 7, 8 arranged in bearings 9, I!) mounted on fixed supports 1 I, It.

An additional disc I3, the diameter of which practically corresponds to that of the refractory drum, is arranged between the latter and the disc 2 and is pressed against the end of the cylindrical portion of the drum by means of push rods is extending freely through the disc 2 and subjected to the action of springs l5 interposed between abutments provided on the push rods and members It arranged outside the disc 2 and connected rigidly to the latter through tie-bolts or the like ll. A sprocket wheel 18 is mounted on the end portion of the trunnion I and is coupled by means of a chain l9 to the power unit 29. Any other suitable mechanism for rotating the furnace may be used instead of the one described. The furnace is provided with one or more loading and discharge doors, not shown in the drawings.

The bars 4 are formed at either end with an ear by means of which they are united to the corresponding disc 2 or 3 through screw bolts or the like.

The end portions of the revolving furnace, viz., the discs and the means for assembling the bars therewith, are arranged outside the heated enclosure, so that the sections of the bars situated inside the said enclosure are free from any mutual bond.

The bars 4, which form the circumferential portion of the metal casing, are spaced apart so that they are able to expand freely, the gaps between the bars being sufiiciently small to enable the bars to provide effective support for the lining 5.

The amount of axial play between the discs 2 and I3 is such as would not be completely resorbed during the maximum differential expansion that may occur in operation between the metal casing and the refractory lining. Owing to the movable disc i3 and to the action of the push rods [4 and the springs 15, a practically constant horizontal thrust is applied to the cylinder 5 made up of refractory blocks, independent from the longitudinal expansion of the bars 4. Owing to the provision of insulating packings E, which always show a certain elasticity, the transfer of heat to the discs 3 and I3 is reduced to the very minimum, while at the same time the danger of the discs getting distorted is eliminated.

The construction according to the invention not only provides for free differential expansion uated degree, which is also due to the provision of the insulating" packing 6. on theinner side ,of each disc. It will be understoodgtherefore, that the bars in each pair of diametrally opposed bars are maintained at a practically invariable mutual distance during heating and cooling periods.

It will be seen'that the invention is not limited to the example described and illustrated and many changes may be made therein without departing from the spirit thereof.

What I claim is:

1. An externally heated revolving furnace including a heated enclosure, a drum-of refractory material in said heated enclosure and an outer metal casing supporting said drum, said casing comprising end'discs arranged outside said heatedenclosure and mutually spaced parallelindividual bars extending through said heated enclosure in close contact with and-supporting theperiphery of said drum and being'connected attheir ends to said end discs, said drum being 10- cated completely in said casing, said end discs being provided with means for rotatably supporting the assembly of said casing and said drum, at least one. end of said drumbeing aXialIyspaced from the corresponding enddiscya'n additional disc movably arranged within said casing in contact with said end of the drum and axially spaced from the corresponding end disc, and pressure springs supported by said end disc for pressing the additional disc against the said end of the drum. 7

-2.. A'furnace, as claimed in claim 1 including means foradjus'ting the tension of said springs 3. A furnace as claimed in claim 1 including push-rods acting upon the additional disc and extending freely through the corresponding end disc, said pressure springs being interposed between abutments integral with the push-rods and thrust-members arranged on the outside of the said end disc and rigidlyfconnected thereto.

4. A furnace asclaimed in claim 1, inwhich the transverse walls of the drum of refractory. material are arranged slightly inwardly ofthe ends of the said drum, a packing of insulating material being interposed between either transversewall and the disc thrust. against the corre-, sponding end of the said drum.

PIERREBEETZJ' References Cited in the file of this been; UNITED STATES PATENTS f l Number Name "Date" q 1,880,768 Burt 'Oct. 4,1932 FOREIGN ATENTS Number A Country- 1 -Date 19,533 Great-Britain i Oct. 4,1890

of i v. he carpi Great Britain June 16,1938. 

